Seeing Quantum Mechanics with the Naked Eye

CAMBRIDGE, England, Jan. 11, 2012 — A new semiconductor chip converts electrons into a quantum, light-emitting state, yet is large enough to see by the naked eye, a development that could lead to a new generation of ultrasensitive gyroscopes.

Quantum mechanics normally shows its influence for tiny particles only at ultralow temperatures, but scientists at the University of Cambridge mixed electrons with light to synthesize supersize quantum particles that behave like superconductors. Building microscopic cavities that tightly trap light into the vicinity of electrons within the chip, they produced lightweight quasiparticles called polaritons that roam freely.

Dual Wave/Particle Nature of Light. (Image: Mebblax from Flickr)
Injecting the polaritons in two laser spots, the researchers found that the resulting quantum fluid spontaneously oscillated backward and forward. In the process, they formed some of the most characteristic quantum pendulum states known to scientists, but thousands of times larger than normal.

“These polaritons overwhelmingly prefer to march in step with each other, entangling themselves quantum mechanically,” said researcher Dr. Gab Christmann.

The quantum liquid that resulted had some peculiar properties, including trying to repel itself. In addition, it could swirl around only in fixed amounts, producing vortices laid out in regular lines.

By moving the laser beams apart, Christmann and his colleagues directly controlled the sloshing of the quantum liquid, which formed a pendulum that could beat a million times faster than a human heart.

“This is not something we ever expected to see directly, and it is miraculous how mirror-perfect our samples have to be,” Christmann said. “We can steer our rivers of polariton quantum liquid on the fly by scanning around the laser beams that create them.”

By increasing the number of laser beams, even more complicated quantum states were created. The goal of the work is to make such quantum states using an electrical battery and at room temperature, which would allow a new generation of ultrasensitive gyroscopes to measure gravity and magnetic field, and to create quantum circuits.

“Just to see and prod quantum mechanics working in front of your eyes is amazing,” Christmann said.